Very much agreed.
Dragonborn are, of course, one of the most obviously non-human races in the game, after all, they've got scales instead of bare skin and ropy scales instead of hair etc. But the only major differences between them and humans (per the 4e lore, as 5e has...kind of avoided much strong lore about non-Tolkien-eque races) are that they eat a larger share of protein (so they need different food sources); they mature earlier than humans, so they can have slightly faster generation turnover (assuming sufficient food); and because they lay eggs, women can be warriors just as much as men, especially when paired with wet-nursing. In terms of sociology, economics, and warfare, dragonborn are basically identical to humans.
A single elf being able to collect wealth for ten bloody times the amount of time a human could? An enormous economic difference. Sociologically, can you imagine how different politics would be if we had to deal, not with the politics of people born in 1940, but people born in 1340? These are people who might be annoyed that the government stopped using French...because they remember that the Parliament of England used French after 1066's invasion by William the Conqueror. They lived through the Wars of the Roses. For them, Shakespeare was a provocative newcomer that these damned kids have normalized. For them, the greatest conflict would probably be Christendom vs Islam, for goodness' sake! Their grandparents would've been Roman citizens!
We've handwaved the incredible alienness of elves (and to a lesser extent dwarves; remember that since they live 200-300 years, for them, the US Civil War is still in living memory) simply because we think we know them well due to Tolkien. Dragonborn and tieflings, in looking more different and not having the titanic juggernaut of Tolkien behind them, can easily feel more alien despite practically being much more similar to regular ol' humans.
Or, to put it differently: We became so obsessed with the rubber foreheads, we overlooked how alien "actually 700 years old" would be.